Although the NCR CRAM article lacks citations, it is very accurate. My first "data processing" job was at Atlanta Federal Savings and Loan in 1972, and we had one of the last NCR 315 machines in production. The CRAM machines, unreliable as they were, had been very competitive with early, and very head-crash-prone, disk drives. By 1972, when I came along, however, the disk drives were much better.